Pi3 and DAC+ Pro

[jimmeuh]

Hi Toby

Read the same issue on the hifiberry forum somewhere. (channel swap thing)
I didn't encounter that problem yet though.

I notice now that wifi is very stable for me, but playback isn't.
Sometimes after boot, I press play, the music just won't start. I reboot from the menu, and afterwards music plays fine.
So It looks like the DAC is still conflicting with the wifi somehow.
Now the wifi got priority over the DAC, while before it was the otherway around.
Nothing usefull in the logs for now....

[tobvc]

Hi jimmeuh,

that behaviour I did not notice up to now, wifi now runs fine on my system. But as the connection seems to be very sensitive to network parameters when a DAC+ pro is connected, the behaviour you observed fits in.
Could someone with background knowledge make a guess where to look for the cause (Hifiberry drivers/Rune/Arch)?

Concerning the channel swap problem: I made a 5 min. long 16 bit FLAC containing a sine tone on the right channel. It is easy noticing the channel swap phenomenon playing this file. Playing it from a local flash drive, I get at least 2 channel swaps per run. Is it possible for you to run it once or twice to check whether you can reproduce the problem? If not, it also could be a hardware defect.

Tobi

[jimmeuh]

Hi Tobi

Tested your file through my mounted cifs share.
Works ok, the tone stays at the right channel.

[tobvc]

Ok, thanks for your testing.

Now that is interesting: both problems (bad wifi + channel swap) seem to be connected in some way. I continued testing different wifi channel configurations on my AP.
With the DAC+ pro activated and the AP on channel 1 or 11, the wifi connection does not work (does that point to any kind of inference?).
In the test runs I made, the channel swap problem seems to appear more often when wifi channels at the beginning or end of the spectrum are used (e.g. ch. 2 or 10). If a channel in the middle of the spectrum (e.g. ch. 6) is used, channel swaps seem to appear much more seldom.

There have been problems with the DAC+ pro and Bluetooth. Is it possible that there are similar problems with wifi? Is there a way to completely disable the wifi chip for futher testing?

Tobi

[hondagx35]

Hi Tobi,

You can disable the drivers by editing the file /etc/modprobe.d/disable_rpi3_wifi_bt.conf:

Code: Select all

##wifi
#blacklist brcmfmac
#blacklist brcmutil
##bt
#blacklist btbcm
#blacklist hci_uart


This will disable wifi:

Code: Select all

##wifi
blacklist brcmfmac
blacklist brcmutil
##bt
#blacklist btbcm
#blacklist hci_uart


Frank

[tobvc]

Thanks Frank.

Unfortunately disabling wifi did not make a change.

Tobi

[jimmeuh]

Just some more testing:

Yesterday I was changing amps and disconnected the pi.
Booted it up, wifi worked fine, no playback. (Press play, nothing happens)
Rebooted several times, still no playback.
Turned it off, reseated the psu, still no playback.
Plugged in LAN cable, no pings on the lan interface. ( ok this was the same as before)
UI didn't respond. not on wlan or lan interfaces. Disconnected the LAN cable again.
Logged in through ssh on the wifi interface, issued a reboot command and after reboot playback was back ok.

I don't get it

At least the wifi still works...

[tobvc]

Have you tried using a different wifi channel?

I have ordered a Pi 2 B and a DAC+ non-pro now to perform further tests.

Tobi

[hondagx35]

Hi Tobi,

I have ordered a Pi 2 B and a DAC+ non-pro now to perform further tests.

I eagerly await your report.

Frank

[tobvc]

The Dac+ (non-pro) was in the mail today. The channel swap problem still occurs in the same way as with the Dac+ pro (Shairport is heavily affected, local 16 bit audio content much less).

On the other hand, wifi seems to work much more stable. Contrary to the system with the DAC+ pro, I even get a stable connection on wifi channels 1 + 11.

So is channel swap a Pi 3/Rune problem, while wifi is affected by the DAC+ pro?

Tobi